Hotfix 0.1.20

Hotfix.

• Far fewer stutters in busy scenes. Effects that write straight to memory (memexport, used by the game's lighting) made the emulator stop and wait for the GPU after every such draw - hundreds to thousands of times per frame. These are now batched and synced only when the game can actually look at the results.
  • Per minute of play: big hitches (frames over 100 ms) 12.7 → 2.6, stutters (over 50 ms) 50 → 4.4.
• New setting slow_frame_log_ms (off by default): logs a breakdown of every frame slower than the given milliseconds. Useful for performance reports.